GM Storm/Spectrum 1985-1993 Repair Guide

Timing Belt

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REMOVAL & INSTALLATION



Although timing belts may last for thousands of miles past the recommended replacement interval, they should be replaced every 60,000 miles to prevent trouble or damage should they snap. Timing belts do not usually give an indication that they are worn or aging without removing the cover(s) and inspecting the belt. A worn or damaged belt could give out at any time. In some cases, should a timing belt snap while the engine is running, damage could be done to the valve trains or pistons requiring a partial or full engine disassembly. Also, should the belt go when the vehicle is far from home, a costly tow or even more costly repair job and considerable inconvenience may be suffered.

Timing belts must always be handled carefully and kept completely free of dirt, grease, fluids and lubricants. This includes any accidental contact from spillage, fingerprints, rags, etc.. These same precautions apply to the pulleys and contact surfaces on which the belt rides.The belt must never be crimped, twisted or bent. Never use tools to pry or wedge the belt into place. Such actions will damage the structure of the belt and possibly cause breakage.

Spectrum

See Figures 1, 2 and 3

The engine must be removed from the vehicle for this procedure to be performed.

  1. Remove the engine and mount it to an engine stand.
  2.  
  3. Remove the accessory drive belts.
  4.  
  5. Remove the engine mounting bracket from the timing cover.
  6.  
  7. Rotate the crankshaft until the notch on the crankshaft pulley aligns with the 0 degree mark on the timing cover and the No. 4 cylinder is on TDC of the compression stroke.
  8.  
  9. Remove the starter and install the flywheel holding tool No. J-35271 or equivalent.
  10.  
  11. Remove the crankshaft bolt, boss and pulley.
  12.  
  13. Remove the timing cover bolts and the timing cover.
  14.  
  15. Loosen the tension pulley bolt.
  16.  
  17. Insert an Allen wrench into the tension pulley hexagonal hole and loosen the timing belt by turning the tension pulley clockwise.
  18.  
  19. Remove the timing belt.
  20.  
  21. Remove the head cover.
  22.  

Inspect the timing belt for signs of cracking, abnormal wear and hardening. Never expose the belt to oil, sunlight or heat. Avoid excessive bending, twisting or stretching.

To install:
  1. Position the Woodruff key in the crankshaft followed by the crankshaft timing gear. Align the groove on the timing gear with the mark on the oil pump.
  2.  
  3. Align the camshaft timing gear mark with the upper surface of the cylinder head and the dowel pin in its uppermost position.
  4.  
  5. Place the timing belt arrow in the direction of the engine rotation and install the timing belt, first to the crankshaft pulley, next to the camshaft pulley, then to the water pump pulley and finally to the tension pulley. Tighten the tension pulley bolt.
  6.  

Once installed, there must be not slack in the timing belt. The belt teeth must be in perfect alignment with the gears.

  1. Turn the crankshaft 2 complete revolutions and realign the crankshaft timing gear groove with the mark on the oil pump.
  2.  
  3. Loosen the tension pulley bolt and apply tension to the belt using an Allen wrench in the hexagonal pulley hole. Torque the pulley bolt to 37 ft. lbs. (50 Nm) while holding the pulley stationary.
  4.  
  5. Check the timing belt tension using a belt tension gauge, it should be 40-48 lbs. (18-22 Kg).
  6.  
  7. Adjust the valve clearances.
  8.  
  9. To complete the installation, reverse the removal procedures. Torque the crankshaft pulley-to-crankshaft bolt to 108 ft. lbs. (147 Nm).
  10.  



Click image to see an enlarged view

Fig. Fig. 1: Timing belt routing - SOHC engines



Click image to see an enlarged view

Fig. Fig. 2: Align the crankshaft timing gear keyway with the mark in the oil pump - SOHC engines



Click image to see an enlarged view

Fig. Fig. 3: Check the timing belt tension at the center of the longest point between pulleys - SOHC engines

Storm
SOHC ENGINE

See Figures 1, 2 and 3

  1. Disconnect the battery negative cable.
  2.  
  3. Remove the timing belt cover. If necessary, raise and support the vehicle, then remove the right under cover to access the lower timing cover bolts.
  4.  
  5. If not done already, rotate the crankshaft so that the No. 4 cylinder is at TDC on its compression stroke by aligning the camshaft pulley timing mark to the 9 o'clock position.
  6.  
  7. Raise and support the vehicle safely.
  8.  
  9. Remove the crankshaft pulley center bolt, the 4 crankshaft pulley side bolts and the crankshaft pulley from the vehicle.
  10.  
  11. Loosen the belt tension pulley bolt, then remove the timing belt from around the tensioner and other pulleys. Remove the timing belt from the vehicle.
  12.  

To install:
  1. Make sure the crankshaft pulley keyway and groove is aligned with the oil pump timing mark and the camshaft pulley timing mark is in the 9 o'clock position. Install the timing belt around the crankshaft timing pulley, followed by the tensioner pulley, water pump pulley and the camshaft timing pulley.
  2.  
  3. Tighten the belt tensioner retaining bolt. Make sure that the belt is properly tightened and is aligned evenly around all the pulleys:
    1. Turn the crankshaft 2 complete revolutions and realign the crankshaft timing gear groove with the mark on the oil pump.
    2.  
    3. Loosen the tension pulley bolt and apply tension to the belt using an Allen wrench in the hexagonal pulley hole. Torque the pulley bolt to 37 ft. lbs. (50 Nm) while holding the pulley stationary.
    4.  
    5. Check the timing belt tension/deflection using a belt tension gauge. The belt should deflect 0.63-0.79 in. (16-20mm) when 22 lbs. (98 N) of pressure is applied to the center of the longest belt stretch.
    6.  

  4.  
  5. Check that the camshaft is still aligned to the 9 o'clock position.
  6.  
  7. Install the timing belt cover, secure it with the 2 lower mounting bolts, then torque the bolts to 89 in. lbs. (10 Nm).
  8.  
  9. Install the crankshaft pulley to the crankshaft dampener, secure the center bolt and the 4 side bolts. Torque the center bolt to 87 ft. lbs. (118 Nm) and the 4 side bolts to 17 ft. lbs. (23 Nm).
  10.  
  11. If removed, install the right side under cover.
  12.  
  13. Lower the vehicle. Install the 4 upper timing belt cover retaining bolts and tighten to 89 inch lbs. (10 Nm).
  14.  
  15. Install the right engine mount.
  16.  
  17. Install the power steering pump drive belt and alternator drive belt. Adjust them to the proper belt tension.
  18.  
  19. Remove engine support fixture and reconnect the negative battery cable.
  20.  

DOHC ENGINE

See Figures 4 and 5

  1. Disconnect the negative battery cable.
  2.  
  3. Install engine support fixture tool J-28467-A or equivalent.
  4.  
  5. Remove the right engine mount.
  6.  
  7. Remove the power steering belt and alternator belt or the serpentine drive belt, as applicable.
  8.  
  9. Remove the upper timing belt cover. If applicable, remove the retaining bolt and relocate the wiring harness from the timing cover.
  10.  
  11. Raise and safely support the vehicle. Remove the right splash shield.
  12.  
  13. Align the crankshaft pulley to TDC, then remove the crankshaft pulley center bolt while holding the pulley from turning. Remove the pulley from the engine.
  14.  

It will be necessary to lower the engine using the support fixture for access to remove the crankshaft pulley.

  1. Lower the vehicle.
  2.  
  3. Remove the lower timing belt cover.
  4.  
  5. Loosen the tensioner pulley retaining bolt 1 / 2 turn and remove the timing belt.
  6.  

To install:
  1. Make sure the camshaft pulleys' timing marks are properly aligned.
  2.  
  3. Install the timing belt to the engine beginning with the crankshaft timing pulley and moving counterclockwise around the pulleys (water pump, idler, exhaust camshaft, intake camshaft) to the tensioner pulley.
  4.  
  5. Install the timing belt tensioner and torque the retaining bolt to 31 ft. lbs. (42 Nm).
  6.  
  7. Rotate the crankshaft 2 turns to ensure that the crankshaft timing pulley mark and the camshaft timing pulley marks are correctly aligned.
  8.  
  9. Install the lower timing belt cover.
  10.  
  11. Raise and safely support the vehicle.
  12.  
  13. Install the crankshaft pulley and torque the center pulley bolt to 87 ft. lbs. (118 Nm). Using the engine support, raise the engine back into position.
  14.  
  15. Lower the vehicle and install the upper timing cover.
  16.  
  17. Install the alternator and power steering belt, then adjust the belts to the proper belt tension or install the serpentine drive belt.
  18.  
  19. Install the right engine mount.
  20.  
  21. Remove the engine support fixture tool. Reconnect the negative battery cable.
  22.  



Click image to see an enlarged view

Fig. Fig. 4: The camshaft pulleys' timing marks must be properly aligned before the timing belt is installed - DOHC engines



Click image to see an enlarged view

Fig. Fig. 5: Timing belt installation order - DOHC engines

 
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